1. Field of the Invention
The present invention relates to an image forming apparatus and a method for converting gradations.
2. Description of the Related Art
In image forming apparatuses using a light emitting diode array (LEDA) that performs a binary write operation, there has been known a technology for performing matrix conversion upon input multivalued image data to convert gradations of the data to binary when the input multivalued image data is output at high resolution. For example, Japanese Patent Application Laid-open No. 2004-155167 discloses a technology for converting multivalued image data to binary or small-valued image data.
However, when matrix conversion is performed to convert gradations, a pattern of matrix may differ depending on whether a write operation is performed in a regular order or in a reverse order which reverses the regular order.
In the light of the foregoing, there is a need to provide an image forming apparatus and a method for converting gradations that can correctly perform gradation conversion when a write operation is performed in either a regular order or a reverse order.